Driving mechanism for picture-exhibiting machines



May 13 1924.

E. L. DUMONT DRIVING MEcHAN'IsM Fori PICTURE EXHIBITING MACHINES mea Dc. 14. 1921 .HMI

Patented May l3, i924.

UNHTED STATES EDWARD L. DUMONT, OF H AVERHILL, MASSACHUSETTS..

DRIVING MECHANISM FOR PICTUR-EXHIBITING MACHINES.

Applicationmeanecember 14, 1921.vk serai No. 522,315.

To all 107mmy t may concern Be it known that I, EDWARD L. DUMONT,

a citizen of the United States, and a resident of Haverhill, county of Essex, State of Massachusetts, have invented an mprovevment in Driving Mechanism` for Picture- Exhibiting Machines, of which the following is a specification.

This invention relates to an intermittent drivingv means for a rotatable disk, or carrier having a seriesof stereopticon plates, or slides mounted therein, in which it is desired to carry the slides successively into position between the light projector and the screen, and hold the disk stationary for the time during which it is desired to exhibit each picture.

The object of the invention is to provide a form of intermittent driving means for the above described purpose which shall consist of a minimum number of w'orkingr parts, so that the expense of construction may be reduced to the lowest point practicable, and also so that a minimum amount of care and attention will be necessary to keep the apparatus in working. order, the machine being thereby especially adapted for advertising purposes.

These objects are accomplished in the manner hereinafter described and as illustrated in the accompanying drawing in which:

Fig. l is a side elevation of a stereopticon of the type above referred to containing a preferred embodiment of the invention.

Fig. 2 is a rear elevation of the driving mechanism.

Fig. 3 is a sectional view at line 3 3 of Fig. 2, on an enlarged scale.

Fig. 4 is a detail view of the locking and releasing mechanism.

In the drawing a indicates a light projector, which is arranged in the rear of a disk or carrier mounted to rotate on a shaft c, and a series of plates l are mounted in holders on the disk in front of regularly spaced and radially disposed apertures therein, said disk being` so arranged with relation to the light projector that the plates may be successively held in the correct relation thereto, and the pictures thereon may be projected onto a screen.

According to the invention, a ratchet wheel e is splined on the shaft c, so that it will be held against rotation on said shaft and a slight longitudinal movement thereon will be permitted. A driving wheel f is mounted to rotate freely on said shaft at one side of said ratchet wheel, and a collar g is secured on the shaft at the opposite side thereof from the ratchet wheel. A coil spring/L is arranged on the shaft o between the hub of the ratchetwheel and one of the bearings i of the shaft, and acts to hold one side of the ratchet wheel in frictional engagement with the adjacent side of the driving wheel, the collar g acting to prevent movement of the latter on the shaft.

An electric motor j, having a worm gear l@ on its shaft, is arranged to engage corresponding gear teeth on the wheel f and, when operated, to drive the wheel f constantly in the direction of the arrow in Fig. 2.

A pawl m is mounted on a pivot n in the frame of the machine and is normally held in engagement with the ratchet wheel e by means of a coil spring 0 and an arm p is secured to the pawl in position to be engaged by a pin g on the wheel b.

The number and arrangement of the teeth on the ratchet wheel correspond to the number and arrangement of the rplates in the wheel and the pawl m is so arranged relatively thereto that, when it is engaged with any one of said teeth, the corresponding plate will be in line with the light rays projected from the light projector a.

Wlhen the machine is to be operated to exhibit the pictures of the plates d suc cessively the motor j is operated to drive the wheel f continuously in the direction indicated, and, as one side of the ratchet wheel is held in frictional engagement with the driving wheel, the latter tends to drive it in the same direction, but, as the ratchet wheel is locked against rotation in this direction by the pawl m, no movement takes place until the pin q on the gear wheel engages the arm 79 and acts to disengage the pawl m from the wheel, as indicated in Fig. 4. When this takes place the frictional engagement between the wheels will be suiiicient to cause the shaft c and with it the carrier to be rotated. As the pin g will immediately become disengaged from the arm j), the pawl will be drawn back into operative position, so that the next tooth on the ratchet wheel will engage the pawl and movement of the carrier b will be arrested at the point at which the neXt plate will be in position in front of the light projector.

This operation may obviously be continued indefinitely, Without attention on the part of an operator, all the plates being successively exhibited for each rotation of the disk `7).

inasmuch as there is constant frictional engagement and slip between the driving and ratchet Wheels, some means for lubrication is provided for the engaging surfaces, and, While any effective means may be employed, a preferable means consists in providing an annular groove r in the engaged side of the ratchet Wheel to which an oil cup e is connected. The apparatus will then require no care or adjustment for long periods.

A friction Washer, as t, is preferably interposed between the Wheels e and f, and these Wheels may be driven in oil, if desired, so that perfect lubrication may be maintained.

I claim:

l. In combination with a rotatably mounted carrier having a series of holders thereon arranged to be successively moved to a predetermined position, a Wheel having a series of teeth corresponding to said series of holders and arranged to rotate said carrier when. driven, a driving Wheel mounted to rotate in axial alignment with said toothed Wheel and constantly frictionally engaged therewith to drive the same, a motor for constantly rotating said driving Wheel in one direction, a locking device arranged to engage the teeth of said toothed Wheel successively to lock the same against rotation when said carrier is in one of said predetermined positions, and means operated by said driving Wheel on each rotation thereof, for temporarily moving said locling device out of operative position, to permit the toothed Wheel to be advanced by the driving Wheel from one locking position to the next.

2. In combination With a rotatably mounted carrier having a series of equally spaced, circularly arranged holders, means for intermittently moving said carrier rotatabiy to bring said holders successively into a predetermined position comprising a ratchet Wheel connected to said carrier and having a series of teeth corresponding in number and position to said holders, a driving Wheel arranged for frietional engagement With said ratchet Wheel to drive the same and cause rotation of the carrier, means for constantly rotating said driving wheel, a. pawl arranged to engage successively the teeth of said ratchet Wheel to hold the same against rotative movement, and means carried by said driving Wheel for moving said paWl to release said ratchet Wheel on each rotation of thel driving Wheel to permit the ratchet Wheel to be driven thereby, said means being arranged to disengage said pawl to permit the same to reengage said ratchet and lock the same when the next succeeding holder has been moved into position. A

lin testimony whereof, I have signed my name to this specification.

EDVARD L. DUMONT. 

